Findings from the StrateGIST 1 trial show that velzatinib (IDRX-42), a broad-spectrum oral therapy, demonstrates strong clinical activity across multiple lines of treatment in patients with advanced gastrointestinal stromal tumors (GIST).
The drug is designed to overcome resistance driven by KIT gene mutations, which account for about 75% to 80% of GIST cases. While current therapies lose effectiveness over time due to secondary resistance mutations, velzatinib targets both primary activating mutations and multiple resistance pathways.
In early-line treatment, the drug achieved an unconfirmed objective response rate of 65% in first-line patients and 40% in second-line patients, with a median progression-free survival of 13.7 months. In later-line settings, response rates remained meaningful, including 27% in third-line therapy and up to 44% in select fourth-line patients without prior exposure to newer agents.
Patients with KIT exon 9 mutations showed particularly strong responses, and those with undetectable circulating tumor DNA at baseline experienced longer progression-free survival. The safety profile was manageable, with a low discontinuation rate.